sort-of-a-solution for local TempoMap context in EditingContext

gtk2_ardour/cue_editor.cc

@@ -1516,7 +1516,6 @@ CueEditor::metric_get_bbt (std::vector<ArdourCanvas::Ruler::Mark>& marks, sample
 		tmap.reset (new Temporal::TempoMap (Temporal::Tempo (120, 4), Temporal::Meter (4, 4)));
 	}
 
-	EditingContext::TempoMapScope tms (*this, tmap);
 	Temporal::TempoMapPoints::const_iterator i;
 
 	char buf[64];

gtk2_ardour/debug.cc

@@ -32,3 +32,4 @@ PBD::DebugBits PBD::DEBUG::GUITiming = PBD::new_debug_bit ("guitiming");
 PBD::DebugBits PBD::DEBUG::EngineControl = PBD::new_debug_bit ("enginecontrol");
 PBD::DebugBits PBD::DEBUG::GuiStartup = PBD::new_debug_bit ("guistartup");
 PBD::DebugBits PBD::DEBUG::TrackDrag = PBD::new_debug_bit ("trackdrag");
+PBD::DebugBits PBD::DEBUG::ScopedTempoMap = PBD::new_debug_bit ("scopedtempomap");

gtk2_ardour/debug.h

@@ -33,6 +33,7 @@ namespace PBD {
                 extern DebugBits EngineControl;
 		extern DebugBits GuiStartup;
 		extern DebugBits TrackDrag;
+		extern DebugBits ScopedTempoMap;
 	}
 }
 

gtk2_ardour/editing_context.cc

@@ -37,6 +37,7 @@
 #include "ardour_ui.h"
 #include "automation_line.h"
 #include "control_point.h"
+#include "debug.h"
 #include "edit_note_dialog.h"
 #include "editing_context.h"
 #include "editing_convert.h"
@@ -153,6 +154,7 @@ EditingContext::EditingContext (std::string const & name)
 	, time_line_group (nullptr)
 	, temporary_zoom_focus_change (false)
  	, _dragging_playhead (false)
+	, local_tempo_map_depth (0)
 
 {
 	using namespace Gtk::Menu_Helpers;
@@ -1752,16 +1754,41 @@ EditingContext::snap_relative_time_to_relative_time (timepos_t const & origin, t
 }
 
 void
-EditingContext::start_local_tempo_map (std::shared_ptr<TempoMap> map)
+EditingContext::start_local_tempo_map (std::shared_ptr<Temporal::TempoMap> map)
 {
 	_local_tempo_map = map;
+	local_tempo_map_in ();
+	DEBUG_TRACE (DEBUG::ScopedTempoMap, string_compose ("%1: starting local tempo scope\n", editor_name()));
 }
 
 void
 EditingContext::end_local_tempo_map ()
 {
+	DEBUG_TRACE (DEBUG::ScopedTempoMap, string_compose ("%1: ending local tempo scope\n", editor_name()));
+	local_tempo_map_depth = 1;
+	local_tempo_map_out ();
+}
+
+void
+EditingContext::local_tempo_map_in () const
+{
+	if (local_tempo_map_depth++ == 0 ) {
+		DEBUG_TRACE (DEBUG::ScopedTempoMap, string_compose ("%1: in to local tempo  %2\n", editor_name(), local_tempo_map_depth));
+		if (_local_tempo_map) {
+			Temporal::TempoMap::set (_local_tempo_map);
 			_local_tempo_map.reset ();
-	Temporal::TempoMap::fetch ();
+		}
+	}
+}
+
+void
+EditingContext::local_tempo_map_out () const
+{
+	DEBUG_TRACE (DEBUG::ScopedTempoMap, string_compose ("%1: out to local tempo  %2\n", editor_name(), local_tempo_map_depth));
+	if (local_tempo_map_depth && --local_tempo_map_depth == 0) {
+		DEBUG_TRACE (DEBUG::ScopedTempoMap, string_compose ("%1: done with local tempo, depth now %2\n", editor_name(), local_tempo_map_depth));
+		Temporal::TempoMap::fetch (); /* get current global map into thread-local pointer */
+	}
 }
 
 bool

gtk2_ardour/editing_context.h

@@ -87,19 +87,6 @@ class EditingContext : public ARDOUR::SessionHandlePtr, public AxisViewProvider,
 
 	Temporal::TimeDomain time_domain () const;
 
-	struct TempoMapScope {
-		TempoMapScope (EditingContext& context, std::shared_ptr<Temporal::TempoMap> map)
-			: ec (context)
-		{
-			ec.start_local_tempo_map (map);
-			ec.ensure_local_tempo_scope ();
-		}
-		~TempoMapScope () {
-			ec.end_local_tempo_map ();
-		}
-		EditingContext& ec;
-	};
-
 	DragManager* drags () const {
 		return _drags;
 	}
@@ -665,9 +652,10 @@ class EditingContext : public ARDOUR::SessionHandlePtr, public AxisViewProvider,
 	QuantizeDialog* quantize_dialog;
 
 	friend struct TempoMapScope;
-	void set_local_tempo_map (std::shared_ptr<Temporal::TempoMap>);
 	void start_local_tempo_map (std::shared_ptr<Temporal::TempoMap>);
 	void end_local_tempo_map ();
+	void local_tempo_map_in () const;
+	void local_tempo_map_out () const;
 
 	virtual bool button_press_handler (ArdourCanvas::Item*, GdkEvent*, ItemType) = 0;
 	virtual bool button_press_handler_1 (ArdourCanvas::Item*, GdkEvent*, ItemType) = 0;
@@ -834,12 +822,20 @@ class EditingContext : public ARDOUR::SessionHandlePtr, public AxisViewProvider,
 	bool _dragging_playhead;
 
 	mutable std::shared_ptr<Temporal::TempoMap> _local_tempo_map;
-	void ensure_local_tempo_scope () const {
+	mutable std::shared_ptr<Temporal::TempoMap> _pre_local_tempo_map;
-		if (_local_tempo_map) {
+	mutable uint64_t local_tempo_map_depth;
-			Temporal::TempoMap::set (_local_tempo_map);
+
+	struct TempoMapScope {
+		TempoMapScope (EditingContext const & context)
+			: ec (context)
+		{
+			ec.local_tempo_map_in ();
 		}
+		~TempoMapScope () {
+			ec.local_tempo_map_out ();
 		}
+		EditingContext const & ec;
+	};
 };
 
-#define EC_LOCAL_TEMPO_SCOPE ensure_local_tempo_scope ()
+#define EC_LOCAL_TEMPO_SCOPE TempoMapScope __tms (*this);
-#define EC_GIVEN_LOCAL_TEMPO_SCOPE(ec) ec.ensure_local_tempo_scope ()

gtk2_ardour/pianoroll.cc

@@ -1481,8 +1481,6 @@ Pianoroll::set_track (std::shared_ptr<ARDOUR::Track> track)
 void
 Pianoroll::set_region (std::shared_ptr<ARDOUR::Region> region)
 {
-	EC_LOCAL_TEMPO_SCOPE;
-
 	CueEditor::set_region (region);
 
 	if (_visible_pending_region) {
@@ -1505,42 +1503,9 @@ Pianoroll::set_region (std::shared_ptr<ARDOUR::Region> region)
 	r->DropReferences.connect (object_connections, invalidator (*this), std::bind (&Pianoroll::unset, this, false), gui_context());
 	r->PropertyChanged.connect (object_connections, invalidator (*this), std::bind (&Pianoroll::region_prop_change, this, _1), gui_context());
 
-	bool provided = false;
-	std::shared_ptr<Temporal::TempoMap> map;
-	std::shared_ptr<SMFSource> smf (std::dynamic_pointer_cast<SMFSource> (r->midi_source()));
-
-	if (smf) {
-		map = smf->tempo_map (provided);
-	}
-
-	if (!provided) {
-		Temporal::TempoMap::SharedPtr tmap (Temporal::TempoMap::use());
-
-		if (with_transport_controls) {
-			/* clip editing, timeline irrelevant, sort of */
-
-			if (tmap->n_tempos() == 1 && tmap->n_meters() == 1) {
-				/* Single entry tempo map, use the values there */
-				map.reset (new Temporal::TempoMap (tmap->tempo_at (timepos_t (0)), tmap->meter_at (timepos_t (0))));
-			}  else {
-
-				map.reset (new Temporal::TempoMap (Temporal::Tempo (120, 4), Temporal::Meter (4, 4)));
-			}
-
-		} else {
-			/* COPY MAIN SESSION TEMPO MAP? */
-			Meter m (tmap->meter_at (r->source_position()));
-			Tempo t (tmap->tempo_at (r->source_position()));
-
-			map.reset (new Temporal::TempoMap (t, m));
-		}
-	}
-
-	{
-		EditingContext::TempoMapScope tms (*this, map);
 	/* Compute zoom level to show entire source plus some margin if possible */
+
 	zoom_to_show (timecnt_t (timepos_t (max_extents_scale() * max_zoom_extent ().second.samples())));
-	}
 
 	bg->display_region (*view);